Method and structure of packaging semiconductor devices

Abstract

A method for fabricating packaged semiconductor devices; attaching a batch-sized metallic grid with openings onto an adhesive tape having an insulating clear core covered by a layer of UV-releasable adhesive, the openings sized larger than a semiconductor chip; attaching a semiconductor chip onto the tape of each window, the chip terminals facing the adhesive surface; laminating insulating material of low coefficient of thermal expansion to fill gaps between each chip and respective grid; turning over assembly to place a carrier under backside of chips and lamination and to remove the tape; plasma-cleaning the assembly front side and sputtering uniform at least one metal layer across the assembly; optionally plating metal layers; and patterning the metal layers to form rerouting traces and extended contact pads for assembly.

I claim: 
     
       1. A semiconductor device comprising:
 a semiconductor chip having a first chip surface with metallized terminals, and a parallel second surface; 
 a frame of insulating material adhering to the sidewalls of the semiconductor chip, the frame having a first surface planar with the first chip surface and a parallel second surface planar with the second chip surface, the first frame surface including one or more embedded metallic fiducials extending from the first frame surface into the insulating material; and 
 at least one film of sputtered metal extending from the terminals across the surface of a polymeric layer to the fiducials, the film patterned to form extended contact pads over the frame and rerouting traces between the chip terminals and the extended contact pads, the film adhering to the surfaces; 
 wherein the metallic fiducials extend from the first frame surface to the parallel second frame surface planar with the second chip surface, conductively connecting the first and the second surface. 
 
     
     
       2. The device of  claim 1  wherein the sputtered film includes a first layer of a metal selected from a group including titanium, tungsten, tantalum, zirconium, chromium, molybdenum, and alloys thereof, the first layer adhering to the chip terminals, polymeric surface, and frame surface; and at least one second layer of a metal selected from a group including copper, silver, gold, and alloys thereof, onto the first layer, the second layer adhering to the first layer. 
     
     
       3. The device of  claim 2  further including at least one layer of plated metal adhering to the sputtered metals. 
     
     
       4. The device of  claim 3  further including a patterned rigid material protecting exposed portions of the layer of insulating material and rerouting traces. 
     
     
       5. The device of  claim 1  wherein the insulating material of the frame includes glass fibers impregnated with a gluey resin having a high modulus and a coefficient of thermal expansion (CTE) close to the CTE of silicon. 
     
     
       6. The device of  claim 1  wherein the configuration and metallurgy of the extended contact pads are selected to be suitable to devices including land grid array devices, ball grid array devices, and Quad Flat No-Lead (QFN) devices.